1640206726771 has 2 divisors, whose sum is σ = 1640206726772. Its totient is φ = 1640206726770.

The previous prime is 1640206726733. The next prime is 1640206726777. The reversal of 1640206726771 is 1776276020461.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1640206726771 is a prime.

It is not a weakly prime, because it can be changed into another prime (1640206726777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820103363385 + 820103363386.

It is an arithmetic number, because the mean of its divisors is an integer number (820103363386).

Almost surely, 2^{1640206726771} is an apocalyptic number.

1640206726771 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640206726771 is an equidigital number, since it uses as much as digits as its factorization.

1640206726771 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1185408, while the sum is 49.

The spelling of 1640206726771 in words is "one trillion, six hundred forty billion, two hundred six million, seven hundred twenty-six thousand, seven hundred seventy-one".